1. Field of the Invention
This invention relates to an abrading cabinet device for use in an abrasive blasting system utilizing a gun for delivering abrasive material within the cabinet against the surface of an article to be abraded, the cabinet device being constructed and arranged to establish a continuing current of air flow downwardly over the article being worked to continuously clear the space above the article of view-obscuring debris from the abrasive blasting operation.
2. Description of the Prior Art
The structure shown in FIG. 1 is illustrative of an abrading cabinet device which is currently commercially available in the marketplace. The cabinet has four sides formed from pieces of sheet metal which are secured together by bolts and nuts or by machine screws. A funnel-shaped bottom is provided for the cabinet which terminates in a collar affording an opening for a container which collects and receives the abrading material and other heavy materials which fall to the bottom of the cabinet during an abrading operation. The cabinet is generally supported by four leg members. A cover member is swingably mounted on the cabinet by a hinge member, and the cover member has a transparent window mounted in its surface so that an operator can view the abrading operation within the cabinet chamber. A rack or grid is generally provided adjacent the top of the funnel-shaped bottom of the cabinet to support the article or work upon which the abrading operation is to be performed. A pair of flexible glove members project through openings in a sidewall at the front of the cabinet and each is secured to its respective opening to provide access for the hands of an operator to operate the gun and to manipulate the article supported on the rack or grid. The gun is conventional. A first hose line is connected to the gun and delivers pressurized air from an external compressor to the gun. A second hose line is also connected to the gun and delivers an abrading material to the gun from an external source so that a rapidly-moving stream of abrading material is delivered from the gun by the pressurized air upon the article supported on the rack.
An exhaust opening is provided in the cover or in the upper portion of one of the sidewalls. A flexible conduit is generally secured to the exhaust opening to lead the dust and airborne debris from the inner chamber of the cabinet. A vacuum is sometimes applied to the exhaust conduit to move the dust and debris to a location remote from the cabinet. The device is environmentally unsound because it produces a great deal of dust and contaminants in the atmosphere exterior of the cabinet. Because of pressurized air from the blasting gun the interior of the cabinet is at a pressure greater than one atmosphere. Furthermore, air flow in the cabinet carries dust and debris upwardly of the cabinet over the article being worked to hinder the view of the operator conducting the abrasive blasting operation.
Another device of which the inventor is aware is shown in U.S. Pat. No. 3,599,375. Again, the exhaust of dust and airborne debris from the abrading operation is at a position in the sidewall of the cabinet above the grid or rack supporting the article worked upon so that the path of the dust and debris continuously obscures the article worked upon during an abrading operation. Furthermore, just as in the prior art device previously described, the air pressure in the cabinet during an abrading operation is at a pressure higher than ambient atmospheric pressure. Thus the stream of air set up within the cabinet, and carrying the dust and air-laden debris, obscures the operator's view of the article being abraded during a blasting operation.